Package ch.bailu.gtk.gobject

Klasse TypePlugin

java.lang.Object
ch.bailu.gtk.type.Type
ch.bailu.gtk.type.Pointer
ch.bailu.gtk.gobject.Object
ch.bailu.gtk.type.PropertyHolder
ch.bailu.gtk.type.Interface
ch.bailu.gtk.gobject.TypePlugin
Alle implementierten Schnittstellen:
PointerInterface
public class TypePlugin extends Interface
An interface that handles the lifecycle of dynamically loaded types.

The GObject type system supports dynamic loading of types.
It goes as follows:

1. The type is initially introduced (usually upon loading the module
the first time, or by your main application that knows what modules
introduces what types), like this:
```c
new_type_id = g_type_register_dynamic (parent_type_id,
"TypeName",
new_type_plugin,
type_flags);
```
where `new_type_plugin` is an implementation of the
`GTypePlugin` interface.

2. The type's implementation is referenced, e.g. through
[func@GObject.TypeClass.ref] or through [func@GObject.type_create_instance]
(this is being called by [ctor@GObject.Object.new]) or through one of the above
done on a type derived from `new_type_id`.

3. This causes the type system to load the type's implementation by calling
[method@GObject.TypePlugin.use] and [method@GObject.TypePlugin.complete_type_info]
on `new_type_plugin`.

4. At some point the type's implementation isn't required anymore, e.g. after
[method@GObject.TypeClass.unref] or [func@GObject.type_free_instance]
(called when the reference count of an instance drops to zero).

5. This causes the type system to throw away the information retrieved
from [method@GObject.TypePlugin.complete_type_info] and then it calls
[method@GObject.TypePlugin.unuse] on `new_type_plugin`.

6. Things may repeat from the second step.

So basically, you need to implement a `GTypePlugin` type that
carries a use_count, once use_count goes from zero to one, you need
to load the implementation to successfully handle the upcoming
[method@GObject.TypePlugin.complete_type_info] call. Later, maybe after
succeeding use/unuse calls, once use_count drops to zero, you can
unload the implementation again. The type system makes sure to call
[method@GObject.TypePlugin.use] and [method@GObject.TypePlugin.complete_type_info]
again when the type is needed again.

[class@GObject.TypeModule] is an implementation of `GTypePlugin` that
already implements most of this except for the actual module loading and
unloading. It even handles multiple registered types per module.

https://docs.gtk.org/gobject/iface.TypePlugin.html

  • Konstruktordetails

  • Methodendetails

    • getClassHandler

      public static ClassHandler getClassHandler()

    • completeInterfaceInfo

      public void completeInterfaceInfo(long instance_type, long interface_type, @Nonnull InterfaceInfo info)
      Calls the @complete_interface_info function from the
      #GTypePluginClass of @plugin. There should be no need to use this
      function outside of the GObject type system itself.
      Parameter:
      instance_type - the #GType of an instantiatable type to which the interface is added
      interface_type - the #GType of the interface whose info is completed
      info - the #GInterfaceInfo to fill in

    • completeTypeInfo

      public void completeTypeInfo(long g_type, @Nonnull TypeInfo info, @Nonnull TypeValueTable value_table)
      Calls the @complete_type_info function from the #GTypePluginClass of @plugin.
      There should be no need to use this function outside of the GObject
      type system itself.
      Parameter:
      g_type - the #GType whose info is completed
      info - the #GTypeInfo struct to fill in
      value_table - the #GTypeValueTable to fill in

    • unuse

      public void unuse()
      Calls the @unuse_plugin function from the #GTypePluginClass of
      @plugin. There should be no need to use this function outside of
      the GObject type system itself.

    • use

      public void use()
      Calls the @use_plugin function from the #GTypePluginClass of
      @plugin. There should be no need to use this function outside of
      the GObject type system itself.

    • getTypeID

      public static long getTypeID()

    • getParentTypeID

      public static long getParentTypeID()

    • getTypeSize

      public static TypeSystem.TypeSize getTypeSize()

    • getParentTypeSize

      public static TypeSystem.TypeSize getParentTypeSize()

    • getInstanceSize

      public static int getInstanceSize()